Exporting Your Uv Mapped Model To .3ds
How to avoid broken vertices

When you export a mesh to .3ds format with "Preserve MAX's Texture Coordinates" enabled, it creates errors in 2 ways.

First up, the UV stitching get corrpted.While the UV co-ordinates themselves remain in place, some of their welds get broken.You can see in the following image, the UV edges(green lines) before export, and after export.

WHile the co-ordinates themselves remain intact, unstitched vertices are slower to render.It also complicates the second problem, which is that the mesh becomes broken along the UV edges.You can see in the following image that the top of the mesh is one single element, however after export it has been broken into multiple elements.

To avoid this, you need to save the UV layout, and export the model with "Preserve MAX's Texture Coordinates" disabled.

To save the UV layout, first apply an Unwrap UVW modifier to the mesh, then in the Parameters rollout, click 'Save'